const path = require("path")
const fs = require("fs");

const DCSInstance = require('./dcsinstance');
const { showErrorPopup, showWaitPopup, showConfirmPopup } = require('./popup');
const { logger } = require("./filesystem")

const ManagerPage = require("./managerpage");
const WizardPage = require("./wizardpage");
const { fetchWithTimeout } = require("./net");
const { exec } = require("child_process");
const { sleep } = require("./utils");

class Manager {
    options = {
        logLocation: path.join(__dirname, "..", "manager.log"),
        configLoaded: false
    };

    activePage = null;
    welcomePage = null;
    settingsPage = null;
    folderPage = null;
    typePage = null;
    connectionsTypePage = null;
    connectionsPage = null;
    passwordsPage = null;
    resultPage = null;
    instancesPage = null;

    constructor() {
        /* Simple framework to define callbacks to events directly in the .ejs files. When an event happens, e.g. a button is clicked, the signal function is called with the function
        to call and an optional object to pass. An event will then be created, defined in index.html, and will be listened here. Using an eval call, the appropriate member function 
        will then be called */
        document.addEventListener("signal", (ev) => {
            const callback = ev.detail.callback;
            const params = JSON.stringify(ev.detail.params);
            try {
                eval(`this.${callback}(${params})`)
            } catch (e) {
                console.error(e);
            }
        });
    }

    /** Asynchronously start the manager
     * 
     */
    async start() {

        /* Check if the options file exists */
        if (fs.existsSync("options.json")) {
            /* Load the options from the json file */
            try {
                this.options = { ...this.options, ...JSON.parse(fs.readFileSync("options.json")) };
                this.options.configLoaded = true;
            } catch (e) {
                logger.error(`An error occurred while reading the options.json file: ${e}`);
                showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`)
            }
        }

        if (!this.options.configLoaded) {
            this.hideLoadingPage();

            /* Show page to select basic vs expert mode */
            this.welcomePage = new ManagerPage(this, "./ejs/welcome.ejs");
            this.welcomePage.show();
        }
        else {
            document.getElementById("header").classList.remove("hide");

            /* Initialize mode switching */
            if (this.options.mode === "basic") {
                document.getElementById("switch-mode").innerText = "Expert mode";
                document.getElementById("switch-mode").onclick = () => { this.switchMode("expert"); }
            }
            else {
                document.getElementById("switch-mode").innerText = "Basic mode";
                document.getElementById("switch-mode").onclick = () => { this.switchMode("basic"); }
            }

            /* Get the list of DCS instances */
            this.setLoadingProgress("Retrieving DCS instances...", 0);
            DCSInstance.getInstances().then(async (instances) => {
                this.setLoadingProgress(`Analysis completed, starting manager...`, 100);
                await sleep(100);

                this.options.instances = instances;

                /* Get my public IP */
                this.getPublicIP().then(
                    (ip) => { this.options.ip = ip; },
                    () => { this.options.ip = undefined; }
                )

                /* Check if there are corrupted or outdated instances */
                if (this.options.instances.some((instance) => {
                    return instance.installed && instance.error;
                })) {
                    /* Ask the user for confirmation */
                    showConfirmPopup("<div style='font-size: 18px; max-width: 100%;'>One or more of your Olympus instances are not up to date! </div> If you have just updated Olympus this is normal. Press Accept and the Manager will update your instances for you. <br> Press Close to update your instances manually using the Installation Wizard", async () => {
                        try {
                            await DCSInstance.fixInstances();
                            location.reload();
                        } catch (err) {
                            logger.error(err);
                            showErrorPopup(`An error occurred while trying to fix your installations. Please reinstall Olympus manually. <br><br> You can find more info in ${this.options.logLocation}`);
                        }
                    })
                }

                this.options.installEnabled = true;
                this.options.editEnabled = this.options.instances.find(instance => instance.installed);

                /* Hide the loading page */
                this.hideLoadingPage();

                this.options.singleInstance = this.options.instances.length === 1;

                /* Create all the HTML pages */
                this.menuPage = new ManagerPage(this, "./ejs/menu.ejs");
                this.folderPage = new WizardPage(this, "./ejs/folder.ejs");
                this.settingsPage = new ManagerPage(this, "./ejs/settings.ejs");
                this.typePage = new WizardPage(this, "./ejs/type.ejs");
                this.connectionsTypePage = new WizardPage(this, "./ejs/connectionsType.ejs");
                this.connectionsPage = new WizardPage(this, "./ejs/connections.ejs");
                this.passwordsPage = new WizardPage(this, "./ejs/passwords.ejs");
                this.resultPage = new ManagerPage(this, "./ejs/result.ejs");
                this.instancesPage = new ManagerPage(this, "./ejs/instances.ejs");

                /* Force the setting of the ports whenever the page is shown */
                this.connectionsPage.options.onShow = () => {
                    if (this.options.activeInstance) {
                        this.setPort('client', this.options.activeInstance.clientPort);
                        this.setPort('backend', this.options.activeInstance.backendPort);
                    }
                }

                if (this.options.mode === "basic") {
                    /* In basic mode no dashboard is shown */
                    this.menuPage.show();
                } else {
                    /* In Expert mode we go directly to the dashboard */
                    this.instancesPage.show();
                    this.updateInstances();
                }

                /* Send an event on manager started */
                document.dispatchEvent(new CustomEvent("managerStarted"));
            });
        }
    }

    /** Get the currently active instance, i.e. the instance that is being edited/installed/removed
     * 
     * @returns The active instance
     */
    getActiveInstance() {
        return this.options.activeInstance;
    }

    /** Creates the options file. This is done only the very first time you start Olympus.
     * 
     * @param {String} mode The mode, either Basic or Expert 
     */
    createOptionsFile(mode) {
        try {
            fs.writeFileSync("options.json", JSON.stringify({ mode: mode, additionalDCSInstances: [] }, null, 2));
            location.reload();
        } catch (err) {
            logger.log(err);
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`)
        }
    }

    /** Switch to a different mode of operation
     * 
     * @param {String} newMode The mode to switch to 
     */
    switchMode(newMode) {
        /* Change the mode in the options.json and reload the page */
        var options = JSON.parse(fs.readFileSync("options.json"));
        options.mode = newMode;
        fs.writeFileSync("options.json", JSON.stringify(options, null, 2));
        location.reload();
    }

    /************************************************/
    /* CALLBACKS                                    */
    /************************************************/
    /** Switch to basic mode
     *  
     */
    onBasicClicked() {
        this.createOptionsFile("basic");
    }

    /** Switch to expert mode
     * 
     */
    onExpertClicked() {
        this.createOptionsFile("expert");
    }

    /** When the install button is clicked go the installation page
     * 
     */
    onInstallMenuClicked() {
        this.options.install = true;

        if (this.options.instances.length == 0) {
            // TODO: show error
        }

        this.options.activeInstance = this.options.instances[0];
        if (this.options.singleInstance) {
            /* Show the type selection page */
            if (!this.options.activeInstance.installed) {
                this.activePage.hide()
                this.typePage.show();
            } else {
                showConfirmPopup("<div style='font-size: 18px; max-width: 100%; margin-bottom: 8px;'> Olympus is already installed in this instance! </div> If you click Accept, it will be installed again and all changes, e.g. custom databases or mods support, will be lost. Are you sure you want to continue?",
                    () => {
                        this.activePage.hide()
                        this.typePage.show();
                    }
                )
            }
        } else {
            /* Show the folder selection page */
            this.activePage.hide()
            this.folderPage.show();
        }
    }

    /** When the edit button is clicked go to the settings page
     * 
     */
    onEditMenuClicked() {
        this.activePage.hide()
        this.options.install = false;
        this.settingsPage.show();
    }

    /** When a folder is selected, find what instance was clicked to set as active
     * 
     * @param {String} name The name of the instance
     */

    async onFolderClicked(name) {
        var instance = await this.getClickedInstance(name);

        var instanceDivs = this.folderPage.getElement().querySelectorAll(".button.radio");
        for (let i = 0; i < instanceDivs.length; i++) {
            instanceDivs[i].classList.toggle('selected', instanceDivs[i].dataset.folder === instance.folder);
            if (instanceDivs[i].dataset.folder === instance.folder)
                this.options.activeInstance = instance;
        }
    }

    /* When the installation type is selected */
    onInstallTypeClicked(type) {
        this.typePage.getElement().querySelector(`.singleplayer`).classList.toggle("selected", type === 'singleplayer');
        this.typePage.getElement().querySelector(`.multiplayer`).classList.toggle("selected", type === 'multiplayer');
        if (this.options.activeInstance)
            this.options.activeInstance.installationType = type;
        else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`);
        }
    }

    /* When the connections type is selected */
    onConnectionsTypeClicked(type) {
        this.connectionsTypePage.getElement().querySelector(`.auto`).classList.toggle("selected", type === 'auto');
        this.connectionsTypePage.getElement().querySelector(`.manual`).classList.toggle("selected", type === 'manual');
        if (this.options.activeInstance)
            this.options.activeInstance.connectionsType = type;
        else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`);
        }
    }

    /* When the next button of a wizard page is clicked */
    onNextClicked() {
        /* Choose which page to show depending on the active page */
        if (this.activePage == this.folderPage) {
            if (this.options.activeInstance.installed) {
                showConfirmPopup("<div style='font-size: 18px; max-width: 100%; margin-bottom: 8px;'> Olympus is already installed in this instance! </div> If you click Accept, it will be installed again and all changes, e.g. custom databases or mods support, will be lost. Are you sure you want to continue?",
                    () => {
                        this.activePage.hide()
                        this.typePage.show();
                    }
                )
            } else {
                this.activePage.hide();
                this.typePage.show();
            }
        } else if (this.activePage == this.typePage) {
            this.activePage.hide();
            this.connectionsTypePage.show();
        } else if (this.activePage == this.connectionsTypePage) {
            if (this.options.activeInstance) {
                if (this.options.activeInstance.connectionsType === 'auto') {
                    this.activePage.hide();
                    this.passwordsPage.show();
                }
                else {
                    this.activePage.hide();
                    this.connectionsPage.show();
                    this.connectionsPage.getElement().querySelector(".backend-address .checkbox").classList.toggle("checked", this.options.activeInstance.backendAddress === '*')
                }
            } else {
                showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`)
            }
        } else if (this.activePage == this.connectionsPage) {
            this.options.activeInstance.checkClientPort().then(
                (portFree) => {
                    if (portFree) {
                        return this.options.activeInstance.checkBackendPort();
                    } else {
                        return Promise.reject('Port not free');
                    }
                }).then((portFree) => {
                    if (portFree) {
                        this.activePage.hide();
                        this.passwordsPage.show();
                    } else {
                        return Promise.reject('Port not free');
                    }
                }).catch(() => {
                    showErrorPopup('Please, make sure both the client and backend ports are free!');
                }
                );
        } else if (this.activePage == this.passwordsPage) {
            if (this.options.activeInstance) {
                if (this.options.activeInstance.installed && !this.options.activeInstance.arePasswordsEdited()) {
                    this.activePage.hide();
                    this.options.install ? this.options.activeInstance.install() : this.options.activeInstance.edit();
                }
                else {
                    if (!this.options.activeInstance.arePasswordsSet()) {
                        showErrorPopup('Please, make sure all passwords are set!');
                    } else if (!this.options.activeInstance.arePasswordsDifferent()) {
                        showErrorPopup('Please, set different passwords for the Game Master, Blue Commander, and Red Commander roles!');
                    } else {
                        this.activePage.hide();
                        this.options.install ? this.options.activeInstance.install() : this.options.activeInstance.edit();
                    }
                }
            } else {
                showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`)
            }
        }
    }

    /* When the back button of a wizard page is clicked */
    onBackClicked() {
        this.activePage.hide();
        this.activePage.previousPage.show(true); // Don't change the previous page
        this.updateInstances();
    }

    onCancelClicked() {
        this.activePage.hide();
        if (this.options.mode === "basic") 
            this.menuPage.show(true);
        else
            this.instancesPage.show(true);
        this.updateInstances();
    }

    onGameMasterPasswordChanged(value) {
        if (this.options.activeInstance) {
            this.options.activeInstance.setGameMasterPassword(value);
            if (!this.options.activeInstance.blueCommanderPasswordEdited)
                this.passwordsPage.getElement().querySelector(".blue-commander input").value = "";
            if (!this.options.activeInstance.redCommanderPasswordEdited)
                this.passwordsPage.getElement().querySelector(".red-commander input").value = "";
        }
        else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`);
        }
    }

    onBlueCommanderPasswordChanged(value) {
        if (this.options.activeInstance) {
            this.options.activeInstance.setBlueCommanderPassword(value);
            if (!this.options.activeInstance.gameMasterPasswordEdited)
                this.passwordsPage.getElement().querySelector(".game-master input").value = "";
            if (!this.options.activeInstance.redCommanderPasswordEdited)
                this.passwordsPage.getElement().querySelector(".red-commander input").value = "";
        }
        else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`);
        }
    }

    onRedCommanderPasswordChanged(value) {
        if (this.options.activeInstance) {
            this.options.activeInstance.setRedCommanderPassword(value);
            if (!this.options.activeInstance.gameMasterPasswordEdited)
                this.passwordsPage.getElement().querySelector(".game-master input").value = "";
            if (!this.options.activeInstance.blueCommanderPasswordEdited)
                this.passwordsPage.getElement().querySelector(".blue-commander input").value = "";
        }
        else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`);
        }
    }

    /* When the client port input value is changed */
    onClientPortChanged(value) {
        this.setPort('client', Number(value));
    }

    /* When the backend port input value is changed */
    onBackendPortChanged(value) {
        this.setPort('backend', Number(value));
    }

    /* When the "Enable API connection" checkbox is clicked */
    onEnableAPIClicked() {
        if (this.options.activeInstance) {
            if (this.options.activeInstance.backendAddress === 'localhost') {
                this.options.activeInstance.backendAddress = '*';
            } else {
                this.options.activeInstance.backendAddress = 'localhost';
            }
            this.connectionsPage.getElement().querySelector(".note.warning").classList.toggle("hide", this.options.activeInstance.backendAddress !== '*')
            this.connectionsPage.getElement().querySelector(".backend-address .checkbox").classList.toggle("checked", this.options.activeInstance.backendAddress === '*')
        } else {
            showErrorPopup(`A critical error occurred, check ${this.options.logLocation} for more info.`)
        }
    }

    /* When the "Return to manager" button is pressed */
    onReturnClicked() {
        location.reload();
    }

    /* When the "Close manager" button is pressed */
    onCloseManagerClicked() {
        document.querySelector('.close').click();
    }

    async onStartServerClicked(name) {
        var div = await this.getClickedInstanceDiv(name);
        div.querySelector(".collapse").classList.add("loading")
        var instance = await this.getClickedInstance(name);
        instance.startServer();
    }

    async onStartClientClicked(name) {
        var div = await this.getClickedInstanceDiv(name);
        div.querySelector(".collapse").classList.add("loading")
        var instance = await this.getClickedInstance(name);
        instance.startClient();
    }

    async onOpenBrowserClicked(name) {
        var instance = await this.getClickedInstance(name);
        exec(`start http://localhost:${instance.clientPort}`)
    }

    async onStopClicked(name) {
        var instance = await this.getClickedInstance(name);
        instance.stop();
    }

    async onEditClicked(name) {
        var instance = await this.getClickedInstance(name);
        if (instance.webserverOnline || instance.backendOnline) {
            showErrorPopup("Error, the selected Olympus instance is currently active, please stop Olympus before editing it!")
        } else {
            this.options.activeInstance = instance;
            this.options.install = false;
            this.activePage.hide();
            this.typePage.show();
        }
    }

    async onInstallClicked(name) {
        var instance = await this.getClickedInstance(name);
        this.options.activeInstance = instance;
        this.options.install = true;
        this.options.singleInstance = false;
        this.activePage.hide();
        this.typePage.show();
    }

    async onUninstallClicked(name) {
        var instance = await this.getClickedInstance(name);

        if (instance.webserverOnline || instance.backendOnline)
            showErrorPopup("Error, the selected Olympus instance is currently active, please stop Olympus before uninstalling it!")
        else
            await instance.uninstall();
    }

    onLinkClicked(url) {
        exec(`start ${url}`);
    }

    onTextFileClicked(path) {
        exec(`notepad "${path}"`);
    }

    async getClickedInstance(name) {
        var instances = await DCSInstance.getInstances()
        return instances.find((instance) => { return instance.name === name; });
    }

    async getClickedInstanceDiv(name) {
        var instance = await this.getClickedInstance(name);
        var instanceDivs = this.instancesPage.getElement().querySelectorAll(`.option`);
        for (let i = 0; i < instanceDivs.length; i++) {
            var instanceDiv = instanceDivs[i];
            if (instanceDiv.dataset.folder === instance.folder) {
                return instanceDiv;
            }
        }
    }

    /* Set the selected port to the dcs instance */
    async setPort(port, value) {
        var success;
        if (port === 'client') {
            success = await this.options.activeInstance.checkClientPort(value);
            this.options.activeInstance.setClientPort(value);
        }
        else {
            success = await this.options.activeInstance.checkBackendPort(value);
            this.options.activeInstance.setBackendPort(value);
        }

        var successEls = this.connectionsPage.getElement().querySelector(`.${port}-port`).querySelectorAll(".success");
        for (let i = 0; i < successEls.length; i++) {
            successEls[i].classList.toggle("hide", !success);
        }
        var errorEls = this.connectionsPage.getElement().querySelector(`.${port}-port`).querySelectorAll(".error");
        for (let i = 0; i < errorEls.length; i++) {
            errorEls[i].classList.toggle("hide", success);
        }
    }

    async getPublicIP() {
        const res = await fetchWithTimeout("https://ipecho.io/json", { timeout: 2500 });
        const data = await res.json();
        return data.ip;
    }

    updateInstances() {
        var instanceDivs = this.instancesPage.getElement().querySelectorAll(`.option`);
        for (let i = 0; i < instanceDivs.length; i++) {
            var instanceDiv = instanceDivs[i];
            var instance = this.options.instances.find((instance) => { return instance.folder === instanceDivs[i].dataset.folder; })
            if (instance) {
                instanceDiv.querySelector(".button.install").classList.toggle("hide", instance.installed);
                instanceDiv.querySelector(".button.start").classList.toggle("hide", !instance.installed);
                instanceDiv.querySelector(".button.uninstall").classList.toggle("hide", !instance.installed);
                instanceDiv.querySelector(".button.edit").classList.toggle("hide", !instance.installed);

                if (instance.installed) {
                    if (instanceDiv.querySelector(".webserver.online") !== null) {
                        instanceDiv.querySelector(".webserver.online").classList.toggle("hide", !instance.webserverOnline);
                        instanceDiv.querySelector(".webserver.offline").classList.toggle("hide", instance.webserverOnline);
                        instanceDiv.querySelector(".backend.online").classList.toggle("hide", !instance.backendOnline);
                        instanceDiv.querySelector(".backend.offline").classList.toggle("hide", instance.backendOnline);

                        if (instance.backendOnline) {
                            instanceDiv.querySelector(".fps .data").innerText = instance.fps;
                            instanceDiv.querySelector(".load .data").innerText = instance.load;
                        }

                        instanceDiv.querySelector(".button.start").classList.toggle("hide", instance.webserverOnline);
                        instanceDiv.querySelector(".button.uninstall").classList.toggle("hide", instance.webserverOnline);
                        instanceDiv.querySelector(".button.edit").classList.toggle("hide", instance.webserverOnline);
                        instanceDiv.querySelector(".button.open-browser").classList.toggle("hide", !instance.webserverOnline);
                        instanceDiv.querySelector(".button.stop").classList.toggle("hide", !instance.webserverOnline);

                        if (instance.webserverOnline)
                            instanceDiv.querySelector(".button.start").classList.remove("loading");
                    }
                }
            }
        }
    }

    reload() {
        this.activePage.show();
    }

    setLoadingProgress(message, percent) {
        document.querySelector("#loader .loading-message").innerHTML = message;
        if (percent) {
            var style = document.querySelector('#loader .loading-bar').style;
            style.setProperty('--percent', `${percent}%`);
        }
    }

    hideLoadingPage() {
        /* Hide the loading page */
        document.getElementById("loader").style.opacity = "0%";
        window.setTimeout(() => {
            document.getElementById("loader").classList.add("hide");
        }, 200);        
    }
}

module.exports = Manager;